Safety treatment device for thermal runaway flue gas and electric equipment

Abstract

The invention discloses a thermal runaway flue gas safety treatment device and electric equipment. The safe treatment device for the thermal runaway flue gas comprises a purification tank and a mixed exhaust unit, a purifying agent is contained in the purifying tank, carbonic ester and solid particles carried in thermal runaway flue gas are filtered by the purifying agent after the battery is subjected to thermal runaway, and a gas part is discharged out of the purifying tank and then enters the mixed exhaust unit; the mixed exhaust unit is used for mixing the purified thermal runaway flue gas with safe gas to form mixed gas and discharging the mixed gas to the external environment; the concentration of combustible gas in the mixed gas is below an explosion lower limit value, so that the risk of combustion and explosion after the thermal runaway flue gas is discharged out of the external environment is avoided, and meanwhile, the pollution of the thermal runaway flue gas directly discharged to the external environment to the atmosphere is also greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, and specifically relates to a thermal runaway flue gas safety treatment device and electrical equipment. Background Technology

[0002] Lithium-ion batteries, as a highly efficient and portable energy storage device, have a wide range of applications. They are mainly used in electric vehicles, energy storage devices, aerospace, and other fields.

[0003] Lithium-ion batteries are better suited for public transportation and cost-sensitive applications due to their safety, durability and cost advantages;

[0004] Lithium-ion batteries may still be at risk of thermal runaway due to mechanical, electrical, and thermal abuse, as well as their own defects. If thermal runaway occurs and is not handled effectively, it can cause a safety accident and threaten the personal safety of people in the vicinity. In addition, the fumes from thermal runaway contain flammable gases, and if not dealt with in time, the probability of combustion and explosion is high. Summary of the Invention

[0005] In order to address the safety hazards posed by thermal runaway in existing lithium-ion batteries, the first aspect of this invention provides a thermal runaway flue gas safety treatment device.

[0006] This thermal runaway flue gas safety treatment device, used for lithium-ion batteries, includes a purification tank and a mixed exhaust unit;

[0007] The purification tank contains a purification agent. After the battery experiences thermal runaway, the carbonates and solid particles carried in the thermal runaway flue gas are filtered by the purification agent. The gas is partially discharged from the purification tank and then enters the mixed exhaust unit.

[0008] The mixed exhaust unit mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas that is then discharged into the external environment; the concentration of combustible gas in the mixed gas is below the lower explosive limit.

[0009] This invention utilizes a purification tank to first purify the carbonates (which may be in vapor or liquid form) carried by the thermal runaway flue gas, preventing further decomposition of the carbonates and thus reducing the content of combustible gases in the thermal runaway flue gas. Then, the remaining unpurified thermal runaway flue gas is discharged from the purification tank and enters the mixing exhaust unit. The mixing exhaust unit fully mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas. The concentration of combustible gases in this mixed gas is reduced to below the lower explosive limit, avoiding the risk of combustion and explosion after the thermal runaway flue gas is discharged into the external environment. At the same time, it also greatly reduces the pollution of the atmosphere caused by the direct discharge of thermal runaway flue gas into the external environment.

[0010] Secondly, in the post-purification mixing step, the purification process can reduce the content of combustible gas in the thermal runaway flue gas entering the mixing emission unit to a certain extent, further reducing the content of combustible gas in the mixed gas after mixing with the safe gas, thereby increasing the possibility that the combustible gas is below the lower explosive limit, making the emission safer.

[0011] Furthermore, the aforementioned purifying agent is an alkaline solution, which is used to filter acidic gases and carbonates in the thermal runaway flue gas. Since acidic gases such as carbonates, hydrogen sulfide, hydrogen fluoride, and CO2 in the thermal runaway flue gas are heavier than air and tend to sink within the purification tank, they will neutralize with the alkaline solution in the purifying agent. This prevents carbonate overflow from potentially causing thermal runaway in nearby batteries, and also avoids environmental pollution and personal injury caused by the emission of hydrogen sulfide, hydrogen fluoride, and CO2.

[0012] Furthermore, due to the presence of the purification tank, some solid particles in the thermal runaway flue gas can also settle into the purification tank by gravity.

[0013] Furthermore, the above-mentioned alkaline solution is a 0.1 mol / L NaOH solution.

[0014] Furthermore, the aforementioned mixed exhaust unit includes a main pipe and at least one branch pipe; the main pipe is installed vertically, with its lower end connected to the thermal runaway flue gas inlet of the purification tank, and its upper end serving as the mixed gas outlet. One end of the branch pipe is connected to the main pipe, and the other end serves as a safety gas inlet. Since hydrogen and carbon monoxide have the highest concentrations of combustible gases in the thermal runaway flue gas, and tend to rise within the purification tank before being discharged into the main pipe, rapidly injecting safety gas into the main pipe through the branch pipe can reduce the concentration of combustible gases such as hydrogen and carbon monoxide to below the lower explosive limit, thus avoiding potential combustion and explosion problems caused by directly discharging the thermal runaway flue gas.

[0015] Furthermore, in order to fully mix the thermal runaway flue gas and the safety gas, the main pipe consists of a first pipe section, a mixing section, and a second pipe section from top to bottom; there are two or more branch pipes, evenly distributed along the circumference; the inner diameter of the mixing section is greater than the inner diameter of the second pipe section, which is greater than the inner diameter of the first pipe section.

[0016] Furthermore, to save on the cost of handling thermal runaway flue gas, the aforementioned safety gas is air; to increase the air injection volume and velocity, as well as the mixing speed of air and thermal runaway flue gas in the main pipe, the safety gas inlet of the aforementioned branch pipe is equipped with a non-powered exhaust fan. The non-powered exhaust fan is installed in a manner that ensures only ambient air can enter the main pipe.

[0017] A second aspect of the present invention provides an electrical device including a plurality of individual batteries, a thermal runaway emission pipeline, and a thermal runaway flue gas safety treatment device as described in the first aspect.

[0018] The thermal runaway flue gas safety treatment device includes a purification tank and a mixed exhaust unit;

[0019] The thermal runaway discharge pipeline includes a main pipe and multiple branch pipes;

[0020] Each individual cell is connected to a branch pipe, which covers the explosion vent of the individual cell; the thermal runaway flue gas outlet of the main pipe is connected to the purification tank.

[0021] A mixing exhaust unit is installed on the top of the purification tank.

[0022] In this electrical equipment, the thermal runaway flue gas is discharged to the mixed exhaust unit through branch pipes and main pipes, which eliminates the possibility that the electrolyte ejected from a single cell during thermal runaway may come into contact with adjacent cells, thus avoiding the problem of thermal runaway spreading due to short circuits or abnormal chemical reactions in adjacent cells.

[0023] Meanwhile, purifying the carbonates carried by the thermal runaway flue gas (which may be in vapor or liquid form) through the purification tank can prevent the carbonates from continuing to decompose, thereby reducing the content of combustible gases in the thermal runaway flue gas.

[0024] Next, the mixed exhaust unit thoroughly mixes the purified thermal runaway flue gas with the safety gas to form a mixed gas. The concentration of combustible gas in this mixed gas is reduced to below the lower explosive limit, avoiding the risk of combustion and explosion after the thermal runaway flue gas is discharged into the external environment. At the same time, it greatly reduces the pollution of the atmosphere caused by the direct discharge of thermal runaway flue gas into the external environment.

[0025] Finally, in the step of purification followed by mixing, the purification process can reduce the content of combustible gases in the thermal runaway flue gas entering the mixing and emission unit to a certain extent, further reducing the content of combustible gases in the mixed gas after mixing with the safe gas, thereby increasing the possibility that the combustible gases are below the lower explosive limit, making the emission safer. Furthermore, the aforementioned multiple individual batteries are located within a housing, while the purification tank and mixing and exhaust unit are located outside the housing. The main pipe in the thermal runaway emission pipeline transports the thermal runaway flue gas outside the housing before it enters the purification tank.

[0026] A third aspect of the present invention provides an electrical device, characterized in that it includes an energy storage cabinet, a thermal runaway emission pipeline, multiple battery packs, and a thermal runaway flue gas safety treatment device as described in the first aspect.

[0027] The thermal runaway flue gas safety treatment device includes a purification tank and a mixed exhaust unit;

[0028] The thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe;

[0029] Multiple battery packs are installed inside the energy storage cabinet; at least the mixing exhaust unit in the thermal runaway flue gas safety treatment device is located outside the energy storage cabinet.

[0030] The battery pack includes a housing, a venting conduit, and multiple individual batteries; the multiple individual batteries are located in a housing, and multiple flue gas inlets on the venting conduit cover the venting section of each individual battery, and the flue gas outlet of the venting conduit is connected to the flue gas outlet of the battery pack.

[0031] Thermal runaway flue gas is sequentially transported from the explosion relief pipe, branch pipe, and main pipe to the purification tank, where the carbonate and solid particles carried in the thermal runaway flue gas are filtered. The gaseous portion of the thermal runaway flue gas enters the mixing exhaust unit and mixes with the safety gas.

[0032] In this electrical equipment, the thermal runaway gas is discharged to the outside of the battery pack through the explosion relief pipeline, which eliminates the possibility that the electrolyte ejected from a single cell in the battery pack during thermal runaway may come into contact with adjacent cells, thus avoiding the problem of thermal runaway spreading in the battery pack due to short circuits or abnormal chemical reactions in adjacent cells.

[0033] In addition, by setting up branch pipes and main pipes, the thermal runaway flue gas is discharged outside the energy storage cabinet, eliminating the possibility that the sprayed electrolyte may come into contact with some electrical components inside the energy storage cabinet. This avoids the corrosion of electrical components inside the energy storage cabinet by the electrolyte and also avoids the problem of thermal runaway caused by short circuits in electrical components spreading inside the energy storage cabinet.

[0034] Meanwhile, purifying the carbonates carried by the thermal runaway flue gas (which may be in vapor or liquid form) through the purification tank can prevent the carbonates from continuing to decompose, thereby reducing the content of combustible gases in the thermal runaway flue gas.

[0035] Next, the mixed exhaust unit thoroughly mixes the purified thermal runaway flue gas with the safety gas to form a mixed gas. The concentration of combustible gas in this mixed gas is reduced to below the lower explosive limit, avoiding the risk of combustion and explosion after the thermal runaway flue gas is discharged into the external environment. At the same time, it greatly reduces the pollution of the atmosphere caused by the direct discharge of thermal runaway flue gas into the external environment.

[0036] Finally, in the step of purification followed by mixing, the purification process can reduce the content of combustible gas in the thermal runaway flue gas entering the mixing emission unit to a certain extent, further reducing the content of combustible gas in the mixed gas after mixing with the safe gas, thereby increasing the possibility that the combustible gas is below the lower explosive limit, making the emission safer.

[0037] Furthermore, the aforementioned mixed emission unit is located above the energy storage cabinet, with its mixed gas outlet facing the sky and at least 1 meter above the top of the energy storage cabinet. This arrangement of the mixed emission unit further ensures the safety of the mixed gas after it is emitted from the energy storage cabinet. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structural principle of Example 1;

[0039] Figure 2 This is a structural schematic diagram of Example 2;

[0040] Figure 3 This is a schematic diagram of the structural principle of Example 3.

[0041] Figure 4 This is a structural schematic diagram of Example 4.

[0042] The attached figures are labeled as follows:

[0043] 100-Purification tank, 200-Mixed exhaust unit, 210-Main pipe, 211-Branch pipe, 212-First pipe section, 213-Mixed section, 214-Second pipe section, 215-Non-powered exhaust fan, 1-T-way pipe assembly, 2-First-stage exhaust fan, 11-First pipeline, 12-Second pipeline, 13-Third pipeline, 14-Second-stage exhaust fan, 300-Thermal runaway discharge pipeline, 301-Branch pipe, 302-Main pipe, 400-Battery pack, 500-Single battery, 600-Shell, 700-Energy storage cabinet, 800-Explosion relief pipeline. Detailed Implementation

[0044] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0045] The phrase "other embodiments" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0046] In this specification, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection, an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0047] Furthermore, in the description of this invention, it should be noted that the terms "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] When a battery experiences thermal runaway, there are currently two main methods for handling it:

[0049] Measure 1: This measure is currently widely used. Specifically, it uses fire-fighting media such as heptafluoropropane, perfluorohexanone, fine water mist, and aerosol to suppress thermal runaway. However, this method has high fire-fighting costs, especially when combined with the widely used perfluorohexanone fire extinguishing medium, which will cause a sharp increase in the cost of handling thermal runaway.

[0050] Measure 2: Existing technologies have proposed a relatively cost-effective method for large-scale energy storage power generation stations. Since the external environment of the station is relatively open, when the battery experiences thermal runaway, the thermal runaway flue gas can be directly discharged into the external environment. However, the application of this solution has significant limitations. For example, if this solution is applied to electric vehicle charging stations, industrial and commercial energy storage, etc., the external environment of these scenarios is relatively complex, and equipment such as photovoltaic panels and charging piles may generate static electricity, which could lead to a greater risk of danger.

[0051] Since both of the above methods have their own problems, the present invention provides a thermal runaway flue gas safety treatment device. The device filters the carbonate and solid particles carried in the thermal runaway flue gas after the battery thermal runaway by using the purifying agent in the purification tank. After the gas is discharged from the purification tank, it enters and mixes with the safety gas to form a mixed gas (the concentration of combustible gas in the mixed gas is reduced to below the lower explosive limit) and is then discharged into the external environment.

[0052] It should be noted that:

[0053] 1. A lithium-ion battery can be a commercially available single cell, such as a prismatic lithium-ion battery, a pouch battery, or a cylindrical battery; it can also be a battery pack, which is generally composed of multiple single cells connected in series, parallel, or mixed connections; or it can be a high-capacity battery proposed in the prior art, which is composed of multiple single cells connected in parallel, and the multiple single cells are in a shared electrolyte system.

[0054] 2. During thermal runaway, a series of violent chemical reactions occur inside the lithium-ion battery, generating a large amount of heat and flammable and toxic gases. These gases include, but are not limited to, hydrogen (H2), carbon monoxide (CO), methane (CH4), and other hydrocarbons. When these gases mix with air within a specific concentration range, they may form an explosive mixture.

[0055] The explosion limits refer to the concentration range within which thermally runaway flue gas, when mixed with air, can explode upon contact with an ignition source. This range typically has a lower limit and an upper limit, known as the lower explosive limit (LEL) and the upper explosive limit (UEL), respectively. When the concentration of combustible gas is below the LEL, the mixture is too lean to support combustion; when the concentration is above the UEL, the mixture is too rich, lacking sufficient oxygen, and also unable to support combustion.

[0056] Experimental results show that the lower explosive limit of the mixed gas generated during thermal runaway of lithium iron phosphate batteries is 6.80%, and the upper explosive limit is 40.63%. This means that when the concentration of the mixed gas is below 6.80%, an explosion will not occur; and when the concentration is above 40.63%, an explosion will also not occur. An explosion is only possible within the concentration range of 6.80% to 40.63%.

[0057] In addition to gases such as hydrogen, CO, and methane, thermal runaway flue gas also contains carbonates (carbonates are generally in vapor or liquid form). If carbonates are not treated, they will undergo a series of decomposition reactions, which will continue to produce a large amount of harmful and flammable gases.

[0058] 3. Safety gases can be inert gases such as nitrogen, carbon dioxide, or air. Using inert gases or carbon dioxide as safety gases offers higher safety than using air. However, due to the large volume of safety gases used, using air as a safety gas is less expensive than using inert gases or carbon dioxide.

[0059] 4. The external environment mentioned in the text refers to the atmospheric environment. Ideally, it should be a relatively open, spacious environment.

[0060] This invention provides the following types of thermal runaway flue gas safety treatment devices and specific embodiments of their application in electrical equipment.

[0061] Example 1

[0062] This embodiment provides a thermal runaway flue gas safety treatment device, such as... Figure 1 As shown, the thermal runaway flue gas safety treatment device includes a purification tank 100 and a mixing exhaust unit 200;

[0063] The purification tank 100 contains a purification agent, and the purification tank 100 is provided with a thermal runaway flue gas inlet and a thermal runaway flue gas outlet. In this embodiment, the purification agent is injected into the purification tank 800 in advance. In some other embodiments, the purification agent can also be introduced into the purification tank by spraying when the thermal runaway flue gas enters the purification tank.

[0064] After a thermal runaway occurs in the battery, the thermal runaway flue gas is transported to the purification tank 100 through the thermal runaway emission pipeline 300. The carbonate and solid particles carried in the thermal runaway flue gas are filtered by the purifying agent, and the gas portion is discharged from the purification tank 100 and enters the mixed exhaust unit. Preferably, a section of the thermal runaway emission pipeline 300 is inserted into the purification tank 100 from the thermal runaway flue gas inlet and is immersed in the purifying agent (the inlet of the section of the thermal runaway emission pipeline 300 is as close as possible to the bottom of the purification tank). The thermal runaway flue gas outlet of the purification tank 100 is used to connect with the mixed exhaust unit 200.

[0065] In this embodiment, the purification tank 100 contains an alkaline solution, which may be an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, etc. This alkaline solution can not only dissolve the carbonate in the flue gas from the thermal runaway of the battery, but also has a good treatment effect on acidic gases such as CO2 and HF.

[0066] Taking NaOH solution as an example, when thermal runaway flue gas is transported to NaOH solution, the NaOH solution reacts with acidic substances such as carbonates, CO2, and HF in the flue gas. For example, carbonates react with NaOH solution: CHOOCR + NaOH = RCOONa + CHOH; CO2 reacts with NaOH solution: 2NaOH + CO2 = Na2CO3 + H2O; subsequently, CO2 also reacts: Na2CO3 + CO2 + H2O = 2NaHCO3; HF reacts with NaOH solution: NaOH + HF = NaF + H2O. Through these reactions, the carbonates and acidic gases in the thermal runaway flue gas are neutralized, significantly reducing subsequent treatment costs.

[0067] Extensive battery thermal runaway tests were conducted, and the effects of water and different concentrations of NaOH solution on the treatment of thermal runaway flue gas were compared. It was found that the gas volume collected after treatment with 0.05–0.5 mol / L NaOH solution was the smallest, the effect was significant after treatment with 0.1–0.2 mol / L NaOH solution, and the effect was the best after treatment with 0.1 mol / L NaOH solution.

[0068] Table 1. Unprocessed runaway data of fully charged 32650 batteries

[0069]

[0070] Table 2 Results of treatment with NaOH solutions of different concentrations

[0071]

[0072]

[0073] Based on the above experimental data, it was found that the volume of gas collected after the thermal runaway of a fully charged 32650 battery without any treatment was 4L. When the thermal runaway gas from a fully charged 32650 battery was passed through a NaOH solution with a concentration of 0.5 mol / L or higher, the collected gas volume was generally greater than 2L, indicating unsatisfactory treatment results. After passing the thermal runaway gas from a fully charged 32650 battery through a NaOH solution with a concentration of 0.05–0.5 mol / L, the gas volume was significantly smaller, all below 2L. Treatment with 0.1–0.2 mol / L sodium hydroxide showed significant effects, with the smallest collected gas volume (approximately 1L) after treatment with 0.1 mol / L sodium hydroxide, demonstrating the best effect. Therefore, a 0.05–0.5 mol / L NaOH solution has a good treatment effect on the thermal runaway gas from a battery.

[0074] Besides alkaline solutions, the principle of "like dissolves like" can be used to treat carbonate liquids or vapors carried in thermal runaway flue gas using organic substances. The organic solvent can be at least one of ester solvents, alcohol solvents, or aldehyde solvents. Specifically, the ester solvent can be methyl salicylate or diethyl phthalate, and the alcohol solvent can be isoamyl alcohol, benzyl alcohol, isobutanol, or isooctanol. However, the adsorption capacity of these organic substances for carbonates is weaker than that of alkaline solutions, and they also cannot absorb acidic gases.

[0075] The mixed exhaust unit 200 mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas that is then discharged into the external environment; the concentration of combustible gas in the mixed gas is reduced to below the lower limit of the explosion limit.

[0076] In this embodiment, the mixed exhaust unit 200 includes a main pipe 210 and at least one branch pipe 211. The main pipe 210 is installed vertically, with its lower end connected to the thermal runaway flue gas inlet of the purification tank 100 and its upper end serving as the mixed gas outlet. One end of the branch pipe 211 is connected to the main pipe 210, and the other end serves as the safety gas inlet. While the purified thermal runaway flue gas enters the main pipe 210, the branch pipe 211 injects a large amount of safety gas into the main pipe 210, thereby reducing the concentration of combustible gas in the formed mixed gas to below the lower explosive limit before it is safely discharged to the external environment.

[0077] Preferably, in order to provide a sufficiently large space within the main pipe 210 for mixing the thermal runaway flue gas and the safety gas, in this embodiment, the main pipe 210 includes, from top to bottom, a first pipe section 212, a mixing section 213, and a second pipe section 214, with the inner diameter of the mixing section 213 > the inner diameter of the second pipe section 214 > the inner diameter of the first pipe section 212; in order to allow as much safety gas as possible to enter the main pipe 210, in this embodiment, two or more branch pipes 211 can be provided on the main pipe 210, and they are evenly distributed along the circumferential direction.

[0078] Preferably, in this embodiment, air is used as the safety gas while also considering cost savings.

[0079] Preferably, in this embodiment, a non-powered exhaust fan 215 is provided at the safety gas inlet of the branch pipe 211. The non-powered exhaust fan 215 is installed in a way that ensures that only ambient air can enter the main pipe. The non-powered exhaust fan 215 can increase the amount of ambient air entering the main pipe 210 per unit time. At the same time, the non-powered exhaust fan 215 has no additional electrical components, which can also avoid the occurrence of danger.

[0080] Example 2

[0081] This embodiment provides a thermal runaway flue gas safety treatment device, which differs from the previous embodiment in that the mixing exhaust unit 200 is different, such as... Figure 2 As shown, the mixed exhaust unit 200 includes a three-way pipe assembly 1 and a primary exhaust fan 2; the three-way pipe assembly 1 includes a first pipe 11, a second pipe 12 and a third pipe 13 that are interconnected; the first pipe 11 serves as a mixed gas exhaust pipe and the primary exhaust fan 2 is installed on the first pipe 11; the second pipe 12 is used to connect with the thermal runaway flue gas outlet of the purification tank, and the third pipe 13 is used to introduce air.

[0082] When the device is in operation, if thermal runaway of the battery is detected, the primary exhaust fan 2 starts working. The thermal runaway flue gas and outside air enter the first pipe 11 to form a mixed gas, which is then discharged into the external environment through the first pipe 11. By pre-setting the pipe diameters of the second pipe 12 and the third pipe 13, as well as the exhaust volume of the primary exhaust fan 2, the concentration of the combustible gas after the air and thermal runaway flue gas mixture is controlled to be below the minimum explosive limit before being discharged into the external environment through the first pipe 11.

[0083] Preferably, to ensure a sufficient amount of air mixes with the thermal runaway flue gas per unit time, a secondary exhaust fan 14 is installed on the third pipeline 13. By turning on the secondary exhaust fan 14, the gas flow rate in the third pipeline 13 per unit time can be increased, which can quickly reduce the concentration of combustible gas in the mixed gas and further improve the safety of the mixed gas discharged into the external environment.

[0084] In some other embodiments, the third conduit 13 may also be connected to a safe gas source containing carbon dioxide or inert gas.

[0085] Example 3

[0086] This embodiment provides an electrical device that uses only one battery pack 400; such as Figure 3 As shown, the electrical equipment mainly includes a battery pack composed of multiple individual batteries 500 connected in series, parallel or mixed, a thermal runaway emission pipeline 300, and a thermal runaway flue gas safety treatment device as described in Examples 1 to 2.

[0087] The thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301; each individual cell 500 is connected to a branch pipe 301, and the branch pipe 301 covers the explosion vent of the individual cell; the thermal runaway flue gas outlet of the main pipe 302 is connected to the purification tank 100 of the thermal runaway flue gas safety treatment device.

[0088] In some embodiments, multiple individual cells 500 in the battery pack 400 are located inside a housing 600, and the thermal runaway flue gas safety treatment device is located outside the housing 600. The main pipe 302 in the thermal runaway emission pipeline 300 transports the thermal runaway flue gas to the outside of the housing 600 and then into the purification tank 100 of the thermal runaway flue gas safety treatment device.

[0089] Example 4

[0090] This embodiment provides an electrical device, which is actually an energy storage device (it can be a residential energy storage, industrial or commercial energy storage, or a power generation-side energy storage device); such as Figure 4 As shown, the electrical equipment includes an energy storage cabinet 700, multiple battery packs 400, a thermal runaway emission pipeline 300, and a thermal runaway flue gas safety treatment device as described in Examples 1 to 2.

[0091] Multiple battery packs 400 are installed inside the energy storage cabinet 700; at least one mixed emission unit in the thermal runaway flue gas safety treatment device is located outside the energy storage cabinet 700;

[0092] Thermal runaway discharge pipeline 300 includes a main pipe 302 and multiple branch pipes 301;

[0093] Each battery pack 400 has a branch pipe 301 connected between its flue gas outlet and the main pipe 302;

[0094] The battery pack 400 includes a housing 600, an explosion venting conduit 800, and multiple individual batteries 500. The multiple individual batteries 500 are located inside a housing 600. Multiple flue gas inlets on the explosion venting conduit 800 cover the explosion venting part of each individual battery 500, and the flue gas outlet of the explosion venting conduit 800 is connected to the flue gas outlet of the battery pack.

[0095] When any single cell in a battery pack experiences thermal runaway, the thermal runaway gas is first discharged from the battery pack through the explosion relief pipeline, and then sequentially discharged from the branch pipe and the main pipe to the thermal runaway flue gas safety treatment device. The thermal runaway flue gas safety treatment device purifies and mixes the thermal runaway flue gas to form a mixed gas that is discharged into the external environment.

[0096] Preferably, in this embodiment, the mixing and emission unit is located above the energy storage cabinet, with the mixed gas outlet of the mixing and emission unit facing the sky and at least 1 meter away from the top of the energy storage cabinet. This arrangement of the mixing and emission unit further ensures the safety of the mixed gas after it is emitted from the energy storage cabinet.

[0097] It should be noted that the explosion relief pipeline in this embodiment is actually similar in structure to the thermal runaway discharge pipeline in embodiment 4, and also includes branch pipes and main pipes; in some other embodiments, a pipeline can also be fixed to the top of each individual cell and cover the explosion relief part of each individual cell.

[0098] In some other embodiments, the battery pack may not have a venting pipe. The thermal runaway gas can be discharged directly to the mixed exhaust unit outside the energy storage cabinet through the thermal runaway exhaust pipe after passing through the battery pack housing. However, this method may cause the thermal runaway to spread inside the battery pack housing, which poses a certain safety hazard.

[0099] In some other embodiments, in order to make the thermal runaway discharge pipeline structure more compact and thus ensure the energy density of the energy storage cabinet, the main pipe in the thermal runaway discharge pipeline may adopt a support frame that supports multiple battery packs.

Claims

1. A thermal runaway flue gas safety treatment device for lithium-ion batteries, characterized in that, Includes a purification tank and a mixed exhaust unit; The purification tank contains a purification agent. After the lithium-ion battery experiences thermal runaway, the carbonates and solid particles carried in the thermal runaway flue gas are filtered by the purification agent. The gas is partially discharged from the purification tank and then enters the mixed exhaust unit. The mixed exhaust unit mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas that is then discharged into the external environment; the concentration of combustible gas in the mixed gas is below the lower explosive limit.

2. The thermal runaway flue gas safety treatment device according to claim 1, characterized in that, The purifying agent is an alkaline solution, which is used to filter out carbonates and acidic gases carried in the thermal runaway flue gas.

3. The thermal runaway flue gas safety treatment device according to claim 1, characterized in that, The alkaline solution is a 0.1 mol / L NaOH solution.

4. A thermal runaway flue gas safety treatment device according to any one of claims 1 to 3, characterized in that, The mixed exhaust unit includes a main pipe and at least one branch pipe; the main pipe is installed vertically, the lower end of the main pipe is connected to the thermal runaway flue gas inlet of the purification tank, the upper end of the main pipe serves as the mixed gas outlet, one end of the branch pipe is connected to the main pipe, and the other end serves as the safety gas inlet.

5. The thermal runaway flue gas safety treatment device according to claim 4, characterized in that, The main pipe includes, from top to bottom, a first pipe section, a mixing section, and a second pipe section; there are two or more branch pipes, which are evenly distributed along the circumference; the inner diameter of the mixing section is greater than the inner diameter of the second pipe section, which is greater than the inner diameter of the first pipe section.

6. The thermal runaway flue gas safety treatment device according to claim 4, characterized in that, The safety gas is air; the safety gas inlet of the branch pipe is equipped with a non-powered exhaust fan.

7. An electrical appliance, characterized in that, Includes multiple individual cells, thermal runaway emission pipelines, and thermal runaway flue gas safety treatment device as described in any one of claims 1 to 6; The thermal runaway flue gas safety treatment device includes a purification tank and a mixed exhaust unit; The thermal runaway discharge pipeline includes a main pipe and multiple branch pipes; Each individual cell is connected to a branch pipe, which covers the explosion vent of the individual cell; the thermal runaway flue gas outlet of the main pipe is connected to the purification tank. A mixing exhaust unit is installed on the top of the purification tank.

8. An electrical appliance according to claim 7, characterized in that, The multiple individual batteries are located inside a housing, while the purification tank and the mixed exhaust unit are located outside the housing. The main pipe in the thermal runaway emission pipeline transports the thermal runaway flue gas to the outside of the housing and then into the purification tank.

9. An electrical appliance, characterized in that, Includes an energy storage cabinet, multiple battery packs, thermal runaway emission pipelines, and a thermal runaway flue gas safety treatment device as described in any one of claims 1 to 6; The thermal runaway flue gas safety treatment device includes a purification tank and a mixed exhaust unit; The thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe; Multiple battery packs are installed inside the energy storage cabinet; at least the mixing exhaust unit in the thermal runaway flue gas safety treatment device is located outside the energy storage cabinet. The battery pack includes a housing, a venting conduit, and multiple individual batteries; the multiple individual batteries are located in a housing, and multiple flue gas inlets on the venting conduit cover the venting section of each individual battery, and the flue gas outlet of the venting conduit is connected to the flue gas outlet of the battery pack. Thermal runaway flue gas is sequentially transported from the explosion relief pipe, branch pipe, and main pipe to the purification tank, where the carbonate and solid particles carried in the thermal runaway flue gas are filtered. The gaseous portion of the thermal runaway flue gas enters the mixing exhaust unit and mixes with the safety gas.

10. An electrical appliance according to claim 9, characterized in that, The mixed exhaust unit is located above the energy storage cabinet, with the mixed gas outlet of the mixed exhaust unit facing the sky and at least 1 meter away from the top of the energy storage cabinet.

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